You must have an exact date, they do not do searches and do not allow researchers access to the records. Use the Family Search index (below) to find your ancestors before you order. DC Department of Heath Vital Records does not do online requests, but you can order DC birth and death records (if they are public) through www.vitalchek.com. Here are the FAQ & Guidelines.

Oak Hill CemeteryOne of DC’s best kept secrets and by far the most beautiful cemetery I have ever been too. Local Georgetown residents often take walks through the gardens. Founded in 1849, the cemetery’s history is mostly of the 19th century with an emphasis on the Civil War. Take a walk through and do a quick google search of any of the headstone names, like Paul J. Pelz or Philip Barton Key and you’ll find some wonderful historical gems! An index of internments is available on their website.

Holy Rood Cemetery (no official website)
Established in 1832 and contains about 7,000 graves, including 1,000 free and enslaved African Americans. This historical cemetery has been neglected for years by it’s current owner, Georgetown University and very few headstones remain. A list of interments can be found at the Georgetown University Special Collections Research Center, open M-F 9am-5pm.